Go see how many people are on lifetime lists as sexual offenders because they got caught pissing in the woods. Or someone saw them naked in their own house through their own window (I didn't make that up).
I don't think anyone would disagree about the clear-cut cases (child rapists... actually any rapists), but once you give the government a powerful tool that follows you your entire life they tend to abuse it.
I would be more comfortable if a committee of trained medical professionals put people on lists or GPS trackers, vs. judges or DAs.